Electrode terminals, such as pins or lead-frames of commercial electric components, are usually pre-coated with a suitable solder, nickel/gold, or a nickel/palladium/gold film, to protect the metal surfaces from oxidation and to provide good solderability. The films are designed and optimized for use at the manufacturers' specified temperature ranges. However, sometimes reliability problems of solder joints arise when the electric components are used above the manufacturers' specified temperature range.
Many commercial electrical components, however, are used in high temperature environments. For example, in the oil and gas industry, downhole tools and equipment normally include electrical components that are used in high temperature oil well environments. Oilfield tool designers typically use commercial electrical components because of their ready availability, even though oil well environments significantly reduce the useful life of the electrical components. There are many factors that influence electrical component life. For high temperature applications, one significant factor is the degradation of the solder joint strength. High temperatures can weaken and break solder joints, causing an electrical failure.